Hose construction and method of forming the same

ABSTRACT

A method of forming a hose construction wherein a peptide surface portion is treated by a nonsolvent material which disrupts the intermoleculer hydrogen bonds between -NH- and -COgroups to soften the surface portion and permit urging of a fibrous second hose element against the softened surface portion to embed the fibrous second portion therein where-upon removal of the treating material permitting reformation of the disrupted intermolecular hydrogen bonds cuases a locked association of the hose elements. The second surface portion is formed of a material substantially inert to the treating material. Also disclosed is a hose construction formed by this method.

1451 Nov. 20, 1973 HOSE CONSTRUCTION AND METHOD OF FORMING THE SAME [75] Inventor: Anil H. Chudgar, Manitowoc, Wis.

[73] Assignee: Imperial-Eastman Corporation,

Chicago, Illinois [22] Filed: Oct. 28, 1971 [21] Appl. No.: 193,492

8/1941 Watson .11. 260/78 sc Primary ExaminerAlfred L. Leavitt Assistant Examiner-C. B. Cosby AttorneyAxel A. Hofgren et al.

[5 7] ABSTRACT A method of forming a hose construction wherein a peptide surface portion is treated by a nonsolvent material which disrupts the intermoleculer hydrogen bonds between --NH- and CO groups to soften the surface portion and permit urging of a fibrous second hose element against the softened surface portion to embed the fibrous second portion therein whereupon removal of the treating material permitting reformation of the disrupted intermolecular hydrogen bonds cuases a loclied 3556156653 the ho se elements. The second surface portion is formed of a material substantially inert to the treating material. Also disclosed is a hose construction formed by this method.

26 Claims, 2 Drawing Figures Patented Nov. 20, 1973 3,773,089

minZ/87ZZ bTj A [2. gy MW HOSE CONSTRUCTION AND METHOD OF FORMING THE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the forming of hose and in particular to the forming of hose having at least one element thereof formed of a material having peptide groups, such as nylon.

2. Description of the Prior Art In one conventional form of hose construction, a reinforcing braid is provided about a tubular core for reinforcing the core. Illustratively, the braid may be formed of a strong plastic material, such as Dacron (polyethylene terephthalates). The core is preferably formed of an impervious material having good fluid carrying characteristics. One example of core material utilized in many conventional hose constructions is nylon, such as nylon 6/6 (polyhexamethylene adipamide). To cause effective bonding between the braid and the nylon core, the core is conventionally heated so as to soften the nylon sufficiently so as to permit the braid to be urged into the outer surface by the tension forces occurring in the normal braiding operation. It has been found to be difficult to obtain uniform heating of the core to assure the desired braid penetration depth. One method of effecting such heating has been to provide a coolant fluid within the core while heat is directed against the exterior portion so as to prevent undue weakening of the entire tubular core by the heating thereof.

Another method of softening the core outer surface has been to dissolve the nylon material with a suitable solvent such as resorcinol, phenol, etc. Here, again, it has been difficult to accurately control the softening depth and the solvation process hastended to produce a weakened hose structure. Furthermore, the intersection at which the filaments are bonded frequently have a swollen appearance, which evidences the solution and redeposition of polymer which is generally referred to as a polymer migration. This adversely affects the bond strength.

SUMMARY OF THE INVENTION The present invention comprehends an improved method of forming a hose construction manufacture avoiding the disadvantages of the above discussed hose construction manufactures in a novel and simple manner while yet providing an improved high strength reinforced hose construction.

More specifically, the invention comprehends the provision of a method of forming a hose construction including the steps of providing a tubular hose element having a polyamide first surface portion having NI-I- CO groups, treating the surface portion to a nonsolvent material, disrupting the intermolecular hydrogen bonds between NH and -CO- groups thereby to soften the surface portion, providing a second hose element having a second surface portion formed of an embeddable material substantially inert to the treating material having a preselected small cross-section suitable to be embedded in the first surface portion, urging the fibrous second surface portion against the treated softened first surface portion of the tubular hose element to embed the fibrous second surface portion in the softened first surface portion of the tubular hose element,

and removing the treating material to cause reformation of the disrupted intermolecular hydrogen bonds of the first surface portion to lock the second hose element surface portion to the first hose element surface portion.

The second hose element may comprise a reinforcing braid. The braid may be formed of a suitable plastic, such as Dacron.

The treating material may comprise a gas. More specifically, the treating material comprises an anhydrous gas, such as a hydrogen halide. The treating material may comprise a mixture of bond-disrupting and inert gases.

The treatment of the polyamide surface portion may be effected by introducing the treating material through the pores of the fibrous second hose element.

BRIEF DESCRIPTION OF THE DRAWING Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:

FIG. 1 is a perspective view of a hose construction embodying the invention; and

FIG. 2 is a schematic diagram illustrating a method of forming a hose construction embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the exemplary embodiment of the invention as shown in the drawing, a hose construction generally designated 10 is shown to comprise a tubular core 11, a reinforcing element 12 disposed concentrically about core 11, and a sheath 13 disposed concentrically about the reinforcing element 12. The invention is concerned with the forming of such a hose construction wherein the reinforcing element 12 is caused to be intimately embedded in either, or both, of the core and sheath elements by a nonsolvent, substantially nontherrnal treatment of the surface portions thereof confronting the reinforcing element.

More specifically, the invention comprehends providing either, or both, of the outer surface portion 14 of core 11 and the inner surface portion 15 of sheath 13 of polyamide material and causing the surface portion to be softened by treating the same with a material suitable to disrupt the intermolecular hydrogen bonds between NH- and -CO groups thereof. The reinforcing material preferably comprises a fibrous reinforcing braid wherein the individual fibers 16 define embeddable elements which, by virtue of the softening of the surface portions 14 and/or 15, are caused to be intimately embedded therein in the manufacturing process. In completing the formation of the hose, the treating material is withdrawn to permit the reformation of the intermolecular hydrogen bond between --NH and CO groups to restore the nylon to the original hard condition but with the braid fibers now firmly embedded therein to provide an improved high strength bonded arrangement.

The braid 12 is preferably formed of a material which is inert to the treating material so that only the surface portions 14 and/or 15 are softened during the manufacturing operation. Illustratively, the braid 12 may be formed of a suitable plastic, such as Dacron (polyethylene terephthalates), metals, such as stainless steel, and the like.

The core portion 14 and sheath portion 15 may be formed of any suitable polyamide having a substantial number of accessible NHCO groups other than fully aromatic polyamides which do not appear to be suitably softened by the treating material possibly due to the rigidity of the molecular structure and or the effect of the aromatic rings on the basicity of the amides groups. Examples of such suitable polyamides are Poly(6-aminocaproic acid (nylon 6), polyhexamethylene adipamide (nylon 6/6), and polyhexamethylene sebacicamide (nylon 6110).

Suitable intermolecular hydrogen bond disrupting materials for use with such polyamides are hydrogen halides, such as anhydrous hydrogen chloride, hydro gen bromide, hydrogen fluoride, hydrogen iodide and boron trichloride; oxides, such as nitrogen dioxide and sulphur and nitrogen trioxide, molecular chlorine, and the like. The treating material may be in gaseous form, one excellent example thereof being gaseous anhydrous hydrogen chloride. The gaseous treating material may be substantially diluted with an inert solvent, such as chloroform, aceton, benzene, and the like, for accurate control of the bond-disrupting action.

To provide accurately controllable uniform treatment of the nylon surface portion, the activating gas is preferably maintained at a temperature of approximately 20 to 25 C. By utilizing anhydrous gaseous materials, solvating action is effectively avoided to maintain a high strength of the surface portion in the hose construction.

As shown in FIG. 2, tube 11 may be delivered to a suitable apparatus for applying the intermolecular hydrogen bond disrupting material to the outer surface portion 14. lllustratively, apparatus 17 may comprise a chamber through which the tube 1 I is passed and containing the gaseous treating material, such as anhydrous hydrogen chloride, at the desired temperature which, as indicated above, may be approximately 20 to 25 C. The treatment of the surface portion may be varied suitably with the concentration of the hydrogen chloride gas, and the pressure thereof and temperature thereat so as to obtain a desired depth of softening. lllustratively, such treatment may be effected in approximately one or two minutes where the hydrogen chloride gas is substantially undiluted and at a pressure of approximately psi. and a temperature in said range. The thusly treated tube is then delivered to an apparatus 18 for providing the reinforcing 12 which, illustratively, may comprise a conventional braider adapted to wrap a suitable material, such as Dacron (polyethylene terephthalates), about the softened core portion 14 under normal manufacturing tension. Thus, the fibrous braid becomes embedded in the softened core poriton 14. The braid covered subassembly 19 is then delivered to a suitable apparatus 20 for removing the hydrogen bond disrupting material. Illustratively, the apparatus 20 may comprise an oven for heating the subassembly 19 suitably to drive off the gaseous bond-disrupting material. Alternatively, the apparatus 20 may comprise a conventional washing apparatus for removing the band-disrupting material by washing it with water, alkaline water, etc., from the subassembly. As the result of the removal of the bond disrupting material from the subassembly 19, the intermolecular hydrogen bonds between the -NH and CO- groups of the core portion 14 are reformed causing the surface portion to regain the normal, relatively hard characteristics of the nylon material but now having the fibers of the reinforcing braid 12 intimately embedded therein so as to provide a positive bonded association of the fibers of the inner portion of the braid E2 to the outer core portion 14. As only the inner braid portion fibers are so embedded, relative movement may be had between the fibers of the braid outwardly thereof providing an improved flexible reinforcement notwithstanding the strong improved bonding of the inner fibers to the core as discussed above.

The sheath 13 may be provided by suitable apparatus 21 illustratively comprising a conventional extruder. Thus, the set subassembly 22 may be delivered from the bond-locking material apparatus 20 to the extruder for application of the sheath. If desired, the outer surface fibers of the braid 12 may be subjected to the hydrogen bond disrupting material immediately prior to the delivery thereof to the extruder 21, such as by passing the set subassembly 22 through the apparatus 17 so that hydrogen bond disrupting material retained in the interstices of the outer portion of the braid 12 may act on the inner surface portion 15 of the extruded sheath to soften the surface portion 15 similarly as core portion 14 by disrupting the intermolecular hydrogen bonds thereof. The treating material may diffuse through the sheath 13 so as to permit reformation of at least a portion of the disrupted intermolecular hydrogen bonds in the final hose construction so as to provide a desired positive bonded association of the braid and sheath. By extruding the sheath 13 directly onto the braid 12, the inner surface portion 15 is caused to flow into the interstices of the braid so as to cause effectively an embedding of the outer braid fibers in the sheath similarly to the embedment of the fibers in the core portion 14.

Because of the inert characteristic of the braid, the intermolecular hydrogen bond disrupting material may be applied through the interstices thereof subsequent to the wrapping of the braid about the core if so desired. Thus, the braid-covered core would be passed through the apparatus 17 to effect the disruption of the hydrogen bonds between NH--- and --CO groups of the underlying nylon core surface portion 14 to form the subassembly 19. As the hydrogen bond disrupting material permeates only the outer surface portion 14, the remainder of the core maintains the original strength thereof during the softening of the outer portion 14 thus avoiding the necessity of providing internal pressure means conventionally used to avoid collapse of the core.

Thus, the present invention comprehends an improved hose construcu'on 10 having highly accurately controlled embedment of the reinforcing fibers in the confronting nylon hose portions to provide an improved high strength reinforced hose. By avoiding a solvation action, the nylon hose elements are caused to have effectively maximum strength in the final hose construction. Further, by permitting highly accurate control of the parameters of the manufacturing operation, the disclosed method permits facilitated highly accurately controlled manufacture of the hose in an extremely simple and novel manner.

The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.

I claim:

l. The method of forming a hose construction comprising the steps of: providing a tubular hose element having a synthetic linear polyamide first surface portion; treating the surface portion to a nonsolvent material disrupting the intermolecular hydrogen bonds between Nl-i and CO groups of said polyamide surface portion thereby to soften said surface portion; providing a second hose element having a second surface portion formed of an embeddable material substantially inert to said treating material having a preselected small cross section suitable to be embedded in said first surface portion; urging said fibrous second surface portion against said treated softened first surface portion of said tubular hose element to embed said fibrous second surface portion in said softened first sur face portion of the tubular hose element; and removing the treating material to cause reformation of the disrupted intermolecular hydrogen bonds of said first surface portion to lock said second hose element surface portion to said first hose element surface portion.

2. The method of forming a hose construction of claim 1 wherein said second hose element comprises a reinforcing braid.

3. The method of forming a hose construction of claim 1 wherein said first hose element comprises a tubular core element and said second hose element comprises a reinforcing braid wrapped thereabout under tension.

4. The method of forming a hose construction of claim 1 wherein said treating material comprises anhydrous hydrogen chloride gas.

5. The method of forming a hose construction of claim 1 wherein said treating material comprises an anhydrous hydrogen halide gas.

6. The method of forming a hose construction of claim 1 wherein said treating material comprises an anhydrous boron trifluoride gas.

7. The method of forming a hose construction of claim 1 wherein said treating material comprises a mixture of intermolecular hydrogen bond disrupting and inert materials.

8. The method of forming a hose construction of claim 1 wherein said second surface portion is urged against said first surface portion prior to the treating step.

9. The method of forming a hose construction of claim 1 wherein said second hose element is porous and said treating material is introduced to said first surface portion through said second porous hose element.

10. The method of forming a hose construction of claim 1 wherein said second hose element is formed of polyethylene terephthalate polyester resin.

11. The method of forming a hose construction of claim 1 wherein said steps are effected continuously.

12. The method of forming a hose construction of claim 1 wherein said treating step is carried out under anhydrous conditions.

13. The method of forming a hose construction of claim 1 wherein said treating material is removed by washing with water.

14. The method of forming a hose construction of claim 1 wherein said treating material is removed by heating.

15. A hose construction formed by the steps of: providing a first tubular hose element having a first synthetic linear polyamide surface portion; treating the surface portion to a material disrupting the intermolecular hydrogen bonds of NH- and CO-- groups of said polyamide surface portion thereby to soften said surface portion; providing a fibrous second hose element having a second surface portion formed of a material substantially inert to said treating material; urging said fibrous second surface portion against said treated softened first surface portion of said tubular hose element to embed the fibrous second surface portion in said softened first surface portion of the tubular hose element; and removing the treating material to cause reformation of the spaced hydrogen bonds of said first surface portion to lock said fibrous second hose element surface portion to said first hose element surface portion.

16. The hose construction of claim 15 wherein said first hose element comprises a core and said second hose element comprises a braid wound onto said core.

17. The hose construction of claim 15 wherein said first hose element surface portion is formed of a material selected from the group of nylon 6, nylon 6/6 and nylon 6/10. I

18. The hose construction of claim 15 wherein said second hose element is formed of polyethylene terephthalate polyester resin.

19. The hose construction of claim 15 wherein said second hose element comprises a reinforcement element.

20. The hose construction of claim 15 wherein said second hose element comprises a spiral wrapped reinforcement.

21. The hose construction of claim 15 wherein said treating material comprises anhydrous hydrogen chloride gas.

22. The hose construction of claim 15 wherein said treating material comprises an anhydrous hydrogen halide gas.

23. The hose construction of claim 15 wherein said treating material comprises an anhydrous boron tritluoride gas.

24. The hose construction of claim 15 wherein said treating material comprises a mixture of intermolecular hydrogen bond disrupting and inert materials.

25. The hose construction of claim 15 wherein said second surface portion is urged against said first surface portion prior to the treating step.

26. The hose construction of claim 15 wherein said second hose element is porous and said treating material is introduced to said first surface portion through said second porous hose element. 

2. The method of forming a hose construction of claim 1 wherein said second hose element comprises a reinforcing braid.
 3. The method of forming a hose construction of claim 1 wherein said first hose element comprises a tubular core element and said second hose element comprises a reinforcing braid wrapped thereabout under tension.
 4. The method of forming a hose construction of claim 1 wherein said treating material comprises anHydrous hydrogen chloride gas.
 5. The method of forming a hose construction of claim 1 wherein said treating material comprises an anhydrous hydrogen halide gas.
 6. The method of forming a hose construction of claim 1 wherein said treating material comprises an anhydrous boron trifluoride gas.
 7. The method of forming a hose construction of claim 1 wherein said treating material comprises a mixture of intermolecular hydrogen bond disrupting and inert materials.
 8. The method of forming a hose construction of claim 1 wherein said second surface portion is urged against said first surface portion prior to the treating step.
 9. The method of forming a hose construction of claim 1 wherein said second hose element is porous and said treating material is introduced to said first surface portion through said second porous hose element.
 10. The method of forming a hose construction of claim 1 wherein said second hose element is formed of polyethylene terephthalate polyester resin.
 11. The method of forming a hose construction of claim 1 wherein said steps are effected continuously.
 12. The method of forming a hose construction of claim 1 wherein said treating step is carried out under anhydrous conditions.
 13. The method of forming a hose construction of claim 1 wherein said treating material is removed by washing with water.
 14. The method of forming a hose construction of claim 1 wherein said treating material is removed by heating.
 15. A hose construction formed by the steps of: providing a first tubular hose element having a first synthetic linear polyamide surface portion; treating the surface portion to a material disrupting the intermolecular hydrogen bonds of -NH- and -CO- groups of said polyamide surface portion thereby to soften said surface portion; providing a fibrous second hose element having a second surface portion formed of a material substantially inert to said treating material; urging said fibrous second surface portion against said treated softened first surface portion of said tubular hose element to embed the fibrous second surface portion in said softened first surface portion of the tubular hose element; and removing the treating material to cause reformation of the spaced hydrogen bonds of said first surface portion to lock said fibrous second hose element surface portion to said first hose element surface portion.
 16. The hose construction of claim 15 wherein said first hose element comprises a core and said second hose element comprises a braid wound onto said core.
 17. The hose construction of claim 15 wherein said first hose element surface portion is formed of a material selected from the group of nylon 6, nylon 6/6 and nylon 6/10.
 18. The hose construction of claim 15 wherein said second hose element is formed of polyethylene terephthalate polyester resin.
 19. The hose construction of claim 15 wherein said second hose element comprises a reinforcement element.
 20. The hose construction of claim 15 wherein said second hose element comprises a spiral wrapped reinforcement.
 21. The hose construction of claim 15 wherein said treating material comprises anhydrous hydrogen chloride gas.
 22. The hose construction of claim 15 wherein said treating material comprises an anhydrous hydrogen halide gas.
 23. The hose construction of claim 15 wherein said treating material comprises an anhydrous boron trifluoride gas.
 24. The hose construction of claim 15 wherein said treating material comprises a mixture of intermolecular hydrogen bond disrupting and inert materials.
 25. The hose construction of claim 15 wherein said second surface portion is urged against said first surface portion prior to the treating step.
 26. The hose construction of claim 15 wherein said second hose element is porous and said treating material is introduced to said first surface portion through said second porous hose element. 